Running Vent Horizontal, UPC

**bengal21** · 07-07-2010, 12:24 PM

I have seen it mentioned that a vent can be run horizontal. I have a basement bathroom and I'm planning to have a sink and shower on one side and a washing machine on the other and a toilet that is wet vent from the washing machine. I cannot run the vent on the sink and shower side of the room to the location where I am going to place the AAV without crossing a doorway. My question is, can i run the vent for the sink and shower up into the floor joists, horizontally across the room and down to meet up with the vent for the washing machine and then run the vent across the room perpindicular to the joists to the AAV? Thanks in advance.

**shacko** · 07-07-2010, 01:16 PM

<<<horizontally across the room and down to meet up with the vent for the washing machine and then run the vent across the room perpindicular to the joists to the AAV? Thanks in advance.<<<

Your vent from your fixture has to be running UP at all times, depending where you live that AAV might be a no-no.

**bengal21** · 07-07-2010, 01:22 PM

I thought that a vent line could be run horizontally if it was 6" above the highest fixture served?

**mighty** · 07-07-2010, 01:40 PM

Yes bengal21 you are quite right that a vent line could be run horizontally provided with 6" above the highest fixture served.

**jimbo** · 07-07-2010, 02:10 PM

make sure about slope...a horizontal section of vent must slope continously downward ( slightly ) towards the drain

**bengal21** · 07-08-2010, 05:16 AM

So, just to be clear, it is acceptable that a vent have a "peak" in the line as long as the lines are sloped toward a drain? Correct?

**nukeman** · 07-08-2010, 05:49 AM

If AAVs are allowed, you could possibly use two of them to make life easier (one on each side of teh wall). However, AAVs usually do not work well for venting pumped sources such a washing machine. They only let air in (not out) and you could have a positive pressure when the washing mashine is draining.

Remember that you will need to be able to access the AAVs and they will need to be able to receive air (using something like an air return grill could take care of both of these requirements). Seriously think about running the vent through the roof. I know it can be difficult on a remodel, but I think you'll be happier if you are able to do it. A real vent allows air to go in both directions.

**Winslow** · 07-09-2010, 08:23 PM

You cannot turn the vent downwards. Additionally unless your local code has ammended the UPC to allow AAV, theu too are illegal. Horizontal wet venting is also not allowed under the UPC.